Online Etymology Dictionary

sack (n.1): "large bag," Old English sacc (West Saxon), sec (Mercian), sæc (Old Kentish) "large cloth bag," also "sackcloth," from Proto-Germanic *sakkiz (source also of Middle Dutch sak, Old High German sac, Old Norse sekkr, but Gothic sakkus probably is directly from Greek), an early borrowing from Latin saccus (also source of Old French sac, Spanish saco, Italian sacco), from Greek sakkos, from Semitic (compare Hebrew saq "sack").

The wide spread of the word is probably due to the Biblical story of Joseph, in which a sack of corn figures (Gen. xliv). Baseball slang sense of "a base" is attested from 1913. Slang meaning "bunk, bed" is from 1825, originally nautical. The verb meaning "go to bed" is recorded from 1946. Sack race attested from 1805.
sack (n.2): "a dismissal from work," 1825, from sack (n.1), perhaps from the notion of the worker going off with his tools in a bag; the original formula was to give (someone) the sack. It is attested earlier in French (on luy a donné son sac, 17c.) and Dutch (iemand de zak geven).
sack (n.4): "sherry," 1530s, alteration of French vin sec "dry wine," from Latin siccus "dry" (see siccative).
sack (v.1): "to plunder," 1540s, from Middle French sac, in the phrase mettre à sac "put it in a bag," a military leader's command to his troops to plunder a city (parallel to Italian sacco, with the same range of meaning), from Vulgar Latin *saccare "to plunder," originally "to put plundered things into a sack," from Latin saccus "bag" (see sack (n.1)). The notion is probably of putting booty in a bag.
sack (n.3): "plunder; act of plundering, the plundering of a city or town after storming and capture," 1540s, from French sac "pillage, plunder," from Italian sacco (see sack (v.1)).
sack (v.2): "put in a bag," late 14c., from sack (n.1). Related: Sacked; sacking.
sack (v.3): "dismiss from work," 1841, from sack (n.2). Related: Sacked; sacking.
sack (v.4): type of U.S. football play, 1969, from sack (v.1) in the sense of "to plunder" or sack (v.2) on the notion of "put in a bag." As a noun from 1972.